From medical necessity to private-sector dominance: a two-decade evolution of caesarean section determinants in Bangladesh (2004-2022).

Caesarean section (CS) is a critical life-saving intervention when medically directed, yet its prevalence in Bangladesh has surged impulsively from approximately 4% in 2004 to nearly 45% in 2022, highlighting a distinctive South Asian pattern of widespread surgical overuse. This study examines the shifting socioeconomic and geographic determinants of CS, specifically investigating the private sector's role in widening inequalities and the transition of surgical birth from a targeted medical necessity to a routine practice dominated by private-sector utilization. We analyzed Bangladesh Demographic and Health Survey (BDHS) data of 26,845 ever-married women, covering the periods 2004-2007, 2011-2014, and 2018-2022. Variables were harmonized and administrative divisions grouped into broader regions to ensure comparability. Using survey-weighted multivariable logistic regression, we identified independent predictors of caesarean section, adjusting for sociodemographic, clinical, and geographic factors while accounting for complex survey design. Weighted CS prevalence increased sharply, rising from 6.8% in 2004-2007 to 39% in 2018-2022. This surge was largely driven by the private sector, where CS rates expanded from roughly 55% in the earliest period to 84% in the most recent. Longitudinal analyses also revealed a notable shift in key determinants: medical indications, initially strong predictors in 2004-2007 (e.g., Multiple Births AOR 9.55), had substantially weaker effects by 2018-2022 (AOR 2.93), indicating growing widespread saturation of CS beyond clinical necessity. The influence of frequent antenatal care similarly declined over time (AOR 9.62 to 4.62), though it remained a significant predictor. Socioeconomic patterns shifted as well; women in the "poorer" wealth quintile moved from having lower odds of CS in 2004-2007 (AOR 0.53) to higher odds in 2018-2022 (AOR 1.45), suggesting increased penetration of surgical delivery into lower-income groups. Geographically, residence in Coastal areas consistently remained protective relative to the Central region. Caesarean delivery in Bangladesh has shifted from a life-saving procedure to a highly prevalent practice, driven predominantly by the expansion of private-sector facilities. An unregulated private sector, rising healthcare contact, and socioeconomic disparities now fuel overuse, demanding stronger regulation, clinical audits, and expanded midwifery‑led care to ensure appropriate use.